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Dr. Gary Kunkel arrives at the Utah State Capitol wearing a breathing mask before a news conference Wednesday, Jan. 23, 2013, in Salt Lake City. A group of doctors is declaring a health emergency over northern Utah's lingering pollution problem. The U.S. Environmental Protection Agency has singled out the greater Salt Lake region as having the nation's worst air for much of January, when an icy fog smothers mountain valleys for days or weeks at a time and traps lung-busting soot. (AP Photo/Rick Bowmer)
/ AP